► First drive of 2015 BMW 3-series facelift► New lights, new engines, minor suspension changes► We test the new range-topping 340i petrol engine

It has changed. Honestly, it has. A second, or maybe third glance, reveals this as the revamped BMW 3-series, fresh from one of the lighter mid-life facelifts you’ll see. New LED lamps and slightly different bumpers front and rear are the main visible updates, while altered suspension, rejigged power steering and a fresh family of engines lie beneath the surface. Oh, and a new cover for the cupholders.

Well, if you were in charge of updating a car that makes up a quarter of BMW sales worldwide today, you’d probably tread pretty carefully too.

So the new engines are the big news – what are they?

Apart from some carry-over six-cylinder diesels, all of the range is built around BMW’s new 500cc-per-cylinder modular Meccano set.

In a first for the 3-series, the line-up now kicks off with a three-cylinder unit, the 1500cc petrol 318i. Then it’s up to two litres and four cylinders for the 320i and 330i before reaching the 3.0-litre, six-cylinder 340i summit. The long-awaited plug-in hybrid petrol-electric 330e won’t arrive until 2016; click here to read our drive of an early prototype.

Diesel power, of course, is where it’s really at commercially for the fleet-king 3-series, and there are five choices: the 2.0-litre, four-cylinder 316d, 320d and 325d, along with the stalwart 3.0-litre six-cylinder 330d and 335d. Four-wheel drive is an option on all but the base engines; the 335d comes with it as standard.

That’s by the by, of course, because everyone’s going to buy the 320d. The Efficient Dynamics edition dips under the all-important 100g/km CO2 threshold with the optional eight-speed auto (102g/km without it) although BMW believes most company car buyers (and, after all, that’s exactly who the bulk of 3-series buyers will be) will be more tempted by the larger-wheeled, bodykit-clad 320d Sport which makes up for its higher price and CO2 output with healthier residuals.

At the launch, the only engine available for us to drive was the 340i. And actually, as it turns out, it’s a bit of a cracker.

Yes, the 340i. What is it?

Replacing the old 335i, the new modular-build straight-six 340i is the fastest 3-series money can buy, short of the all-out M3. It turns out 322bhp and 332lb ft, it’s hooked up to an unflappable (optional) eight-speed automatic gearbox, and it can make the 3-series go hilariously, stupendously quickly.

Not only does it sound like a thoroughbred sports car, with a crunchy fanfare of pops and crackles on the overrun, it goes like one too: goodness me it’s quick. Power delivery is as responsive as it is smooth, with little in the way of turbo lag, and in the mid-range it’s simply devastating.

The 340i starts from £38,125 – not small money, but if you fancy a stealthier-looking alternative to the M3, it’s more than £15k cheaper...

A 330d (which is torquier still) would be the more rational choice for combining performance clout with economy, of course, but make sure you don’t test-drive a 340i first. Leaving reason aside, it’s the engine you’ll want.

What about those suspension changes? They’ve not spoiled the handling, have they?

The geometry hasn’t changed, but the top mounts now shake hands more firmly with the bodyshell for improved torsional rigidity, the ride height’s 10mm lower (but not on 4wd xDrive versions) and the damper units are new – both the standard shocks and the optional adaptive dampers feature new valves and pistons (based on lessons learned in the M235i, we’re told).

The upshots, says BMW, are reduced body roll, improved directional stability and quicker, more precise steering response. The latter’s also down to a retune for the electric power steering system. With the stiffer front suspension assembly taking all of the slack out of the steering’s response, there’s perhaps a little more tendency for the front wheels to follow the road’s cambers more eagerly but it’s no deal-breaker. Muddying the waters slightly was the brand-new optional ‘Variable Sport’ adaptive steering system fitted to all cars at the launch. It’s an extra-cost option which alters the steering’s rate of response according to speed and not all who tried it were enamoured with it, but I never found its responses anything other than consistent and accurate. It’s hardly the abomination of Audi’s Dynamic Steering system, at any rate. Still, try before you buy.

Our test car rode on the optional adaptive dampers, which now offer more of a contrast between the softest Comfort mode and firmer Sport. In the former, the car rode commendably well despite its 18-inch wheels and run-flat tyres.

Most importantly though, the 3-series is still great to drive, with balanced, rewarding handling and classy body control.

Verdict

Yes, the BMW 3-series’ interior is beginning to look a touch dated next to the Jaguar XE’s classy minimalism and the Mercedes C-Class’s swoopy theatre, and by the same token, although the 3-series chassis is still superb, its rivals have closed the gap – we placed the Jaguar XE ahead of the closely related 4-series Gran Coupe in our recent triple test, and the C-Class is hardly a dullard to drive either.

But everything that made the 3-series such a class act before is still there, plus it’s now cleaner and more fuel efficient, and still looks fresh thanks to those handsome new headlights. It was great before and it’s still great now.

And for what it’s worth, the 5% of 3-series buyers who do go for the 340i engine will have a jolly good time.